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Atomika

Ansible scripts amended from https://subok-tech.com/installing-kubernetes-using-ansible-on-ubuntu-20-04/ to boot a local Kubernetes cluster (both windows and linux worker nodes) for use as a shared development environment and/or host for a Spinnaker CI/CD constellation (see https://github.com/jrb-s2c-github/spinnaker_tryout) Tested on Ubuntu 20.04.

Another description on how to use these Ansible playbooks to boot your own out-of-cloud cluster can be read at https://dzone.com/articles/fast-feature-branch-deployments-of-micro-services and https://dzone.com/articles/safe-clones-with-ansible.

Contributing

Should you wish to contribute or improve, feel free to fork and create a pull request back for me to approve. Alternatvely drop me a message on linkedin at https://www.linkedin.com/in/janrb/ to be added as a contributor.

Essentials

1. Edit the inventory file to
   1. add master node, co-master nodes for high availability and worker nodes;
   2. point to location of private key to be found in master key folder (has to be done for each node).
2. Run k8s_containerd_pkg.yml to install and prepare each of the nodes
3. Run k8s_master_init.yml to boot up the master node
4. (Optional) Run k8s_comasters.yml to join the two other master nodes to enable high availability
5. Run k8s_workers.yml to join the worker nodes

Preparing a Linux box to take commands from Ansible

In the multipass folder is a cloud_init.yml file to prepare ubuntu nodes to receive instruction from Ansible. The master key is in the master key folder.

Alternatively, it can be done manually as follows:

New Linux box:

1. Sudo adduser vmadmin
2. Sudo usermod -aG sudo vmadmin
3. sudo update-alternatives --config editor. Select vim should you be unfamiliar with Nano.
4. sudo visudo
5. Add: 'vmadmin ALL=(ALL) NOPASSWD:ALL'
6. test that user can ‘sudo ls /root’ without having to enter password

Copy key from server where ansible commands are ran from:

1. Create public and private keys for user vmadmin using the ssh-keygen command on Ansible server should the keys not yet exist. This private key is the one that should be referenced in the Ansible inventory file.
2. sudo ssh-copy-id -i ./vmadmin_key.pub vmadmin@192.168.68.109
3. test access: sudo ssh vmadmin@192.168.68.109 -i ./vmadmin_key

Adding a multipass VM running on Windows

1. Install multipass on windows
2. Create an external virtual switch in Hyper-V manager. The underlying network adapter can be shared with windows should there not be a secondary network adapter available. This, however, is not optimal as this sharing between two operating system slows down networking. A secondary network adapter dedicated to the multipass virtual machine is recommended. I use an external wifi adapter for this.
3. Run: 'multipass launch --cloud-init cloud_init.yml --cpus 4 --mem 4048M -n zoops1 --network “WiFi 2”'
4. Note the ip address assigned to the external switch and add to vmworkers section in the Atomika inventory file.

Testing Ingress and MetalLB loadbalancer

1. Run 'kubectl get service ingress-nginx-controller --namespace=ingress-nginx' and check that an IP address has been assigned to field "EXTERNAL-IP". This means MetalLB is listening on this IP address.
2. Run 'kubectl create deployment demo --image=httpd --port=80' to install web server
3. Run 'kubectl expose deployment demo' to expose web server as service
4. Run 'kubectl create ingress demo --class=nginx --rule www.demo.io/=demo:80' to create Ingress resource
5. Open www.demo.io inside a web browser on any node in the cluster and check that "It works!" is displayed

See https://kubernetes.github.io/ingress-nginx/deploy/#quick-start for more

References

Read the first two to gain understanding what the two prompts starting the master boot-up are about.

1. https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/high-availability/
2. https://metallb.universe.tf/configuration/
3. https://phoenixnap.com/kb/how-to-create-sudo-user-on-ubuntu#:~:text=Most%20Linux%20systems%2C%20including%20Ubuntu%2C%20have%20a%20user,terminal%2C%20enter%20the%20command%3A%20usermod%20-aG%20sudo%20newuser
4. https://multipass.run/docs/launch-command